We have released the mainnet version of the full node (mwc-node). It can be downloaded here: https://github.com/mwcproject/mwc-node/releases/tag/2.4.3
Previous versions of the full node will not work on mainnet. If you plan to mine on mainnet, please update your full node with this version. As a reminder, mining will begin on 11/11/19 and 9 am UTC.